An antenna array can transform electromagnetic signal into electromagnetic waves that broadcast a radiation pattern and/or produces an electrical signal in response to receiving electromagnetic waves. This radiation pattern can be used to transmit and receive signals.
The performance of an antenna array typically depends on several factors, such as array size, transceiver architecture, assembly methods, availability of a common reference point, and matching, and calibration. Transmit and/or receive alignment, such as on phase and/or amplitude, can affect the transmitter and/or receiver radiation pattern. Accordingly, it is typically desirable to have accurate transmit and receive calibration in an active antenna system.